It is well known that an accurate reading of the temperature of a human body is helpful, if not essential, for the diagnosis and monitoring of numerous ailments. Indeed, several types of thermometers have been developed for these purposes. For instance, one type of reusable thermometer which is being increasingly used is the infrared radiation (IR) thermometer. An exemplary such device is disclosed in U.S. Pat. No. 4,797,840 to Fraden.
Importantly, as with the other types of thermometers, it is necessary that there be a sanitary contact between the IR thermometer and the body during operational use. It is well known that such a sanitary contact can be accomplished in several ways. For example, the thermometer may either be sterilizable prior to a subsequent use, or used only once and then discarded. Additionally, the thermometer may somehow be protected from contact with the body. For IR thermometers which cannot be easily sterilized or are too expensive to be simply thrown away the only practical way to insure subsequent sanitary uses of the thermometer may be to provide a disposable cover or barrier for that part of the thermometer which comes into contact with the body.
Typically, in order to determine the temperature of a human body, IR thermometers use a hollow probe, or speculum, to establish a radiation pathway between a selected body surface and the thermal radiation detecting element of the thermometer. It is this probe which is normally inserted into the ear canal of the patient or otherwise brought into contact with a body surface. Thus, it is the probe of an IR thermometer which needs to be protected from contamination.
Several probe covers have been suggested to accomplish the purpose of providing a sanitary barrier between a patient and the probe of a thermometer. In addition to the sanitary barrier function, these devices typically must also fulfill up to three additional functions. First, the probe cover must typically be transparent to radiation having a wavelength in the far infrared range, i.e. at least part of the probe cover must function as an infrared window. Also, the probe cover must securely attach to the thermometer housing, and it should provide for the easy and comfortable insertion of the probe into a body cavity (e.g. the ear canal).
Previous probe covers have typically used separate components to meet all four requirements, or have not fully met one or more of these requirements. As an example of a probe cover which joins separate components to perform the various probe cover functions discussed above, U.S. Pat. No. 4,662,360 to O'Hara et al. discloses a sanitary protective cover for the ear canal probe of a tympanic thermometer. The O'Hara device, as disclosed, is a multi-part cover which incorporates an essentially rigid side wall that serves as a speculum. One part (the film) of the O'Hara device is used as the infrared window and the other part (the tube) of the O'Hara device is used to fulfill the other three requirements discussed above.
Similarly, U.S. Pat. No. 4,911,559 to Meyst, et al. discloses a three-piece probe cover that has a stretchable film which serves as a sanitary barrier, an infrared window and a probe (speculum) envelope to facilitate insertion of the probe into the ear. The device has a separate rigid ring for securely fitting the probe cover onto the probe.
Still another probe cover is disclosed in U.S. Pat. No. 4,790,324 to O'Hara. It has a tubular body much thicker than a window transparent to infrared radiation and disposed across the outer end of the body. The inner tube end surrounds but is spaced from the probe.
Unfortunately, such multi-part covers require the accomplishment of numerous tasks during the manufacturing procedure. Additionally, when the various parts of a multi-part probe cover are assembled, seams are created along the boundaries of the interconnected parts which, if they protrude excessively from the probe cover, can be uncomfortable for the patient. Perhaps more importantly, the integrity, and therefore the sanitary efficacy, of the Probe cover is likely to be more easily compromised along a seam than in the other surface areas of the cover.
Thus, it is desirable that the probe cover be of unitary construction. One such probe cover is disclosed in U.S. Pat. No. 3,949,740 to Twentier. The Twentier patent discloses a rigid probe cover which covers all but the distal end of the probe. Thus, the Twentier probe establishes an infrared window for its associated probe by not covering the distal end of the probe at all. Unfortunately, because the Twentier device does not cover the distal end of the probe, the distal end may potentially become contaminated during use. Accordingly, there is still a need to provide a unitary probe cover which covers substantially all of the probe of a thermometer to establish an effective sanitary barrier.
The present invention recognizes that an effective unitary probe cover for an IR thermometer can be produced without requiring the assembly of various probe cover parts during the manufacturing process. Further, the present invention recognizes that a sanitary probe cover need not function as a speculum in order to accomplish its protective function. Accordingly, it is an object of the present invention to provide a probe cover which is of unitary construction. Still another object of the present invention to provide a probe cover which establishes a continuous integrally formed unitary barrier between the probe and the surface of the body which would otherwise come into contact with the probe. Finally it is an object of the present invention to provide a probe cover that is relatively easy to use and cost-effective to manufacture.